with zero configuration for my trackball and keyboard (covered in this post), here is the Xorg.0.log snippet :

[  7734.487] (II) config/udev: Adding input device Topre Corporation HHKB Professional (/dev/input/event3)
[  7734.487] (**) Topre Corporation HHKB Professional: Applying InputClass "evdev keyboard catchall"
[  7734.487] (II) Using input driver 'evdev' for 'Topre Corporation HHKB Professional'
[  7734.487] (II) Loading /usr/lib64/xorg/modules/input/evdev_drv.so
[  7734.487] (**) Topre Corporation HHKB Professional: always reports core events
[  7734.487] (**) Topre Corporation HHKB Professional: Device: "/dev/input/event3"
[  7734.491] (--) Topre Corporation HHKB Professional: Found keys
[  7734.491] (II) Topre Corporation HHKB Professional: Configuring as keyboard
[  7734.491] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:12.2/usb1/1-6/1-6.1/1-6.1.1/1-6.1.1:1.0/input/input3/event3"
[  7734.491] (II) XINPUT: Adding extended input device "Topre Corporation HHKB Professional" (type: KEYBOARD)
[  7734.491] (**) Option "xkb_rules" "evdev"
[  7734.491] (**) Option "xkb_model" "evdev"
[  7734.491] (**) Option "xkb_layout" "us"
[  7734.491] (II) config/udev: Adding input device Clearly Superior Technologies. CST Laser Trackball (/dev/input/event2)
[  7734.491] (**) Clearly Superior Technologies. CST Laser Trackball: Applying InputClass "evdev pointer catchall"
[  7734.491] (II) Using input driver 'evdev' for 'Clearly Superior Technologies. CST Laser Trackball'
[  7734.491] (II) Loading /usr/lib64/xorg/modules/input/evdev_drv.so
[  7734.491] (**) Clearly Superior Technologies. CST Laser Trackball: always reports core events
[  7734.491] (**) Clearly Superior Technologies. CST Laser Trackball: Device: "/dev/input/event2"
[  7734.495] (--) Clearly Superior Technologies. CST Laser Trackball: Found 9 mouse buttons
[  7734.495] (--) Clearly Superior Technologies. CST Laser Trackball: Found scroll wheel(s)
[  7734.495] (--) Clearly Superior Technologies. CST Laser Trackball: Found relative axes
[  7734.495] (--) Clearly Superior Technologies. CST Laser Trackball: Found x and y relative axes
[  7734.495] (II) Clearly Superior Technologies. CST Laser Trackball: Configuring as mouse
[  7734.495] (II) Clearly Superior Technologies. CST Laser Trackball: Adding scrollwheel support
[  7734.495] (**) Clearly Superior Technologies. CST Laser Trackball: YAxisMapping: buttons 4 and 5
[  7734.495] (**) Clearly Superior Technologies. CST Laser Trackball: EmulateWheelButton: 4, EmulateWheelInertia: 10, EmulateWheelTimeout: 200
[  7734.495] (**) Option "config_info" "udev:/sys/devices/pci0000:00/0000:00:12.2/usb1/1-6/1-6.2/1-6.2:1.0/input/input2/event2"
[  7734.495] (II) XINPUT: Adding extended input device "Clearly Superior Technologies. CST Laser Trackball" (type: MOUSE)
[  7734.495] (II) Clearly Superior Technologies. CST Laser Trackball: initialized for relative axes.
[  7734.495] (**) Clearly Superior Technologies. CST Laser Trackball: (accel) keeping acceleration scheme 1
[  7734.495] (**) Clearly Superior Technologies. CST Laser Trackball: (accel) acceleration profile 0
[  7734.495] (**) Clearly Superior Technologies. CST Laser Trackball: (accel) acceleration factor: 2.000
[  7734.495] (**) Clearly Superior Technologies. CST Laser Trackball: (accel) acceleration threshold: 4
[  7734.495] (II) config/udev: Adding input device Clearly Superior Technologies. CST Laser Trackball (/dev/input/mouse0)
[  7734.495] (II) No input driver/identifier specified (ignoring)

this is so much nicer then having to specify all settings for specific peripherals like we had to years ago.